At some point, an entrepreneur tackled this problem by making a leather case with rigid sides and additional locks. This turned out to be lighter and much more durable than wooden boxes, as it was flexible. These hinged cases persisted until the advent of airlines, where lighter luggage was needed. This, along with the industrial revolution, led to an explosion of leather goods to cover all the new needs. Business bags and briefcases, writing cases, leather wallets, leather bags, and so on. Also, cases were necessary to protect new gadgets like binoculars, telescopes, cameras, etc. The production of leather goods had already become a thriving industry.